Heater for an automotive vehicle and method of forming same

ABSTRACT

There is disclosed a heater for an automotive vehicle or other article of manufacture. The heater typically includes a first conductive medium and a second conductive medium disposed upon a carrier. In a preferred embodiment, the first conductive medium includes a first section and a second section that are electrically connected by a second conductive medium. The second conductive medium preferably exhibits a positive thermal coefficient.

CLAIM OF PRIORITY

To the extent applicable, the present invention claims the benefit ofthe priority of U.S. Provisional Application Ser. No. 60/428,002, filedNov. 21, 2002 and U.S. Provisional Application Ser. No. 60/474,835,filed May 30, 2003, both of which are incorporated herein by referencefor all purposes.

FIELD OF THE INVENTION

The present invention relates generally to heaters and more particularlyto heaters for use in seats, mirrors, handles or other locations ofautomotive vehicles, transportation vehicles or other articles ofmanufacture.

BACKGROUND OF THE INVENTION

For many years, industry has been concerned with designing improvedheaters for articles of manufacture such as seats, mirrors or handles offurniture, automotive vehicles or other transportation vehicles.Examples of such heaters are disclosed in U.S. Pat. Nos. 6,084,217,5,451,747, 5,045,673, 4,931,627 and 4,857,711 all of which are expresslyincorporated herein by reference for all purposes. However, the heatersdisclosed in these patents suffer from drawbacks. For example, andwithout limitation, U.S. Pat. No. 6,084,217 employs a “polymeric thickfilm” and drawbacks with the implementation of such technology haveshown that heaters employing such films have been relatively inflexible,resulting in the potential for noise resulting from body shifting upon aseating surface. Also, these heaters have traditionally offered only oneheat output level when in use. In the interest of improving uponexisting technology in this field, the present invention provides aheater that is particularly suitable for use in seats of automotivevehicles, but which may be adapted for application in othertransportation vehicles or other articles of manufacture as well.

SUMMARY OF THE INVENTION

According to one aspect of the invention, there is disclosed a heaterand a method of forming the same. For forming the heater, a flexiblecarrier is provided. The carrier is preferably formed of a materialselected from the group consisting of polymeric materials and fabricmaterials. The carrier also preferably includes a first lengthwise edgeopposite a second lengthwise edge wherein both the first and secondlengthwise edge having an indentation with at least one contour. A firstconductive medium is typically disposed upon the carrier. The firstconductive medium is preferably formed of a polymeric material andpreferably includes the following: i) a negative section having a firstbase portion and a plurality of first extensions extending from thefirst base portion, the first base portion extending along the firstlengthwise edge of the carrier along the at least one contour of thefirst lengthwise edge; and ii) a positive section having a second baseportion and a plurality of second extensions extending from the secondbase portion, the second base portion extending along the secondlengthwise edge of the carrier along the at least one contour of thesecond lengthwise edge. A second conductive medium is also preferablydisposed upon the carrier. The second conductive medium typicallyincludes a plurality of strips wherein each of the strips is inoverlapping relation with at least one of the plurality of firstextensions and at least one of the plurality of second extensions.Typically, the second conductive medium has positive thermal coefficientcharacteristics.

According to another aspect of the present invention, the firstconductive medium includes at least a first section, a second sectionand a third section, wherein the sections are spaced apart. Optionally,each section may comprise one or more extensions or combinations. Asecond conductive medium is also disposed upon the carrier and isinterposed between the spaced sections (e.g. between the extensions ofthe sections). As with the previous aspect of the invention, the secondconductive medium typically has positive thermal coefficientcharacteristics.

According to yet another preferred aspect of the invention the heater ofthe present invention is integrated into an article of manufacture. Asan example, the heater may be integrated into a seat of an automotivevehicle. The seat typically includes a foam cushion for a supportcomponent of the vehicle seat and the foam cushion preferably includes acavity formed therein. A trim layer will typically substantially coverthe foam cushion. The heater preferably disposed between the foamcushion and the trim layer. In a preferred embodiment, at least aportion of the heater extends into the cavity of the foam cushionthereby curving the at least one contour of the first base portion ofthe first conductive medium and the at least one contour of the secondbase portion or the first conductive medium.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and inventive aspects of the present invention will becomemore apparent upon reading the following detailed description, claimsand drawings, of which the following is a brief description:

FIG. 1 is a top view of an exemplary partially formed heater inaccordance with an exemplary aspect of the present invention;

FIG. 2 is a top view of the exemplary heater in FIG. 1 after furtherformation of the heater in accordance with an exemplary aspect of thepresent invention;

FIG. 2A is a top view of an exemplary alternative electrical connectionsuitable for a heater of the present invention.

FIG. 3 is a blown up side cross-sectional view of the exemplary heaterof FIGS. 1 and 2 with additional exemplary components in accordance withan exemplary aspect of the present invention;

FIG. 4 is a partially cut away perspective view of a seat of anautomotive vehicle formed in accordance with an exemplary aspect of thepresent invention;

FIG. 5 is a top view of a portion of a seat of an automotive vehicleformed in accordance with an exemplary aspect of the present invention;

FIG. 6 is a top view of an exemplary heater for an automotive mirror inaccordance with an exemplary aspect of the present invention; and

FIG. 7 is a cross-sectional view of a mirror assembly in accordance withan exemplary aspect of the present invention.

FIG. 8 is a top view of a portion of another heater in accordance withan exemplary aspect of the invention.

FIG. 9 is a top view of a portion of yet another heater in accordancewith an exemplary aspect of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is predicated upon providing an improved heatersuitable for integration into a variety of articles of manufacture. Forexample, the heater may be integrated into or attached to carriers(e.g., members, structures, panels, floors, walls or the like) ofvarious articles of manufacture such as buildings, furniture,transportation vehicles (e.g., boats, trains, airplanes, busses) or thelike. Alternatively, the heater may be integrated into or attached tovarious components of transportation vehicles such as seats, mirrors ormirror assemblies (e.g. rearview mirrors, side view mirrors or thelike), gear shifters, panels, footwells, floor mats, cargo or bedliners, windows or other components. The heater is particularly suitablefor integration into a seat of an automotive vehicle. More particularly,the heater is suitable of integration with the seat portion, backportion, head rest portion, or a combination thereof.

In another automotive application, the present invention may be used ina steering assembly. As such, the heater may be placed on or integratedwith various regions of a steering wheel including the hub, wheel,spokes, turn signal or shifter of the steering wheel assembly. Likewise,the heater of the present invention may be located anywhere throughoutthe vehicle, and most advantageously, with components that generallycome in contact with an occupant of the vehicle including arm rest, rearview mirrors, user control interfaces and otherwise.

Outside of the automotive application, it is foreseeable that thepresent invention may be incorporated into other applications includingBed mattresses, wheel chairs, articles of clothing, or any other objectthat may come into contact with a person.

Furthermore, the present invention may be used outside of personalcomfort applications including: infrared sensing technology, heatingelectrical or mechanical components or even heating a fluid through asubmersion of the heater or an application to the outer walls of acontainer. Also, the heater may include or be integrated with: anantenna for reception or transmission of radio frequencies; a sensorsuch as a seat occupant sensor (e.g. for use with an airbag orotherwise), or a sensor for children car seats; a warning device forsignaling an alarm when a temperature (internal or otherwise) of thevehicle is undesirably high or low; combinations thereof or the like. Insome or all of the previous applications, the heater may be configuredwith a pressure sensor to determine the presence of an applied forceacting on the heater or the sensor.

The heater of the present invention may exhibit one or more advantagesas compared to previous heaters. As one example, the heater may controlits heat output without employing components such as a controller, athermostat, a temperature sensor, combinations thereof or the like. Ofcourse, it is contemplated that these components may be included withthe heater to assist in controlling or regulating the amount of heatoutput by the heater. As another advantage, the geometry, sizing,materials and configuration of the heater and its components can assistin forming a more effective heating system within a vehicle seat orother article of manufacture. As an example, a preferred heater may beformed of materials that add flexibility to the heater for assisting inminimizing noise that might otherwise be produced by the heater. Asanother example, a preferred heater may include one or more contours,openings or cavities for aiding the bending of the heater therebyallowing the heater to conform to contours of an article of manufactureparticularly for assisting in attaching the heater to the article.

In one or more alternate embodiments, the heater of the presentinvention may also be adapted to selectively activate one or moreregions of the heater to provide selective heating, to manipulate theheat output generated by the heater or both. In the one or morealternate embodiments, a user can preferably control one or both of thelocation and intensity of heat provided by the heater of the presentinvention.

Generally, the heater of the present invention will include one or acombination of the following components:

-   -   1) a carrier that is preferably configured as a flexible panel;    -   2) a first conductive medium disposed upon the carrier, the        first conductive medium preferably including a first section and        a second section wherein each section preferably includes a base        portion and a plurality of extensions extending from the base        portion;    -   3) a second conductive medium for interconnecting the first        section to the second section, the second conductive medium        preferably including a plurality of resistive strips, which        preferably interconnect the plurality of extensions of the first        section to the plurality of extensions of the second section        wherein the second conductive medium preferably exhibits        positive thermal coefficient characteristics.

Optionally, the first conductive medium can include a third section forassisting the heater in providing multiple heat output levels or forallowing selective heating of different locations of the heater.

Referring to FIGS. 1, 2 and 3, there is illustrated the formation of anexemplary heater 10 in accordance with the present invention. The heater10 includes a first conductive medium 12 and a second conductive medium14 disposed upon a carrier 18. Generally, the heater 10 is configured asa flexible panel (i.e., with opposing surfaces and a thicknesstherebetween) although other shapes or configurations may be employed aswell.

For example, while in one embodiment the carrier 18 may be flexible, itis foreseeable that the carrier may alternatively be rigid or semi-rigidor non existent altogether (discussed in greater detail below).Regardless of the rigidity characteristics of the carrier 18, thecarrier may be formed in numerous shapes and configuration as desireddepending on the application (e.g. seat, seat back, head rest, mirror,steering wheel, or any other article that may be heated to enhance theenvironment for a user). Moreover, the carrier may include contours forassisting in stress relief particularly when the heater may be subjectto stresses from pressure, movement or otherwise.

The carrier 18, as illustrated, is configured as panel with opposingsurfaces 26, 28. As seen in the particular embodiment of FIGS. 1, 2 and5, the carrier 18 is substantially elongated and generally rectangularand more preferably is hourglass shaped. As shown, the carrier 18 has alength (L) and a width (W) and includes an outer peripheral edge 22extending substantially continuously about the carrier 18 substantiallydefining the shape of the carrier 18. The peripheral edge 22 is shown toinclude a first lengthwise edge 32 opposing a second lengthwise edge 34.

In the particular embodiment illustrated, the first lengthwise edge 32and the second lengthwise edge 34 have cutouts for helping to form thehourglass shape. For example, the lengthwise edges 32, 34 respectivelydefine a first indentation 38 and a second indentation 40, whichrespectively define a first concavity 44 and a second concavity 46. Thefirst indentation 38 generally opposes and is substantially a mirrorimage of the second indentation 40. Both indentations 38, 40 may includeone or a plurality of contours 48, 50, 52 at least partially definingthe cavities 44, 46. In the particular embodiment illustrated, bothindentations 38, 40 include two pair of opposing convex contours 48, onepair of opposing concave contours 50 and one central concave contour 52.The carrier 18 may also include an opening 58 located between the firstand second indentations 38, 40 and which is generally rectangular.

The heater, carrier or both may be shaped as desired and such shape maydepend upon the application of the heater. Thus, the carrier or heatershape should not limit the present invention unless otherwise stated. Asexamples, the heater, carrier or both may include configurations thatare circular, oval, elliptical, square, rectangular, geometric,non-geometric, symmetric, or asymmetric, or combinations thereof or thelike. Furthermore, the heater, the carrier or both may be preformed(e.g. as planar or contoured) to correspond to an article such as asteering wheel or other article. Alternatively, the heater, the carrieror both may be flexible to allow of such correspondence.

In a preferred embodiment of the present invention, the carrier may beattached to one or more components of an article of manufacture (e.g. aseat, a mirror or the like). Alternatively, a first carrier may providea release surface, which allows the first and second conductive mediumto be transferred to one or more components of the article such that theone or more components become the carrier. This may be achievedaccording to various techniques such as appliqués, dissolvablesubstrates, removable substrates, or the like. Alternatively, the firstand second conductive medium may be placed on one or more of thecomponents of the article itself through printing, spraying, rolling,dabbing, brushing, pouring, or the like, again such that the one or morecomponents become the carrier of the heater.

It is contemplated that the carrier 18 may be conductive, nonconductive,or partially conductive. This includes electric conductivity, thermalconductivity and diffusion. Also, for attachment purposes, the carriermay be configured to hold and maintain a static charge thereby allowingthe carrier to attach itself to a component of an article (e.g. a mirrorassembly, a seat or the like), with or without the use of adhesion orfastening techniques.

Alternatively, or in combination with the above, the carrier may furtherinclude one or more adhesive materials or layers for attaching thecarrier to a component. The adhesive material may be applied to thecarrier or, the carrier itself may comprise of adhesive material or haveadhesive characteristics. The adhesive may be applied using suchtechniques as printing, spraying, rolling, dabbing, brushing, pouring orotherwise placed on one or both sides of the carrier.

The carrier 18 may be formed from various materials including polymericmaterials such as plastics, elastomers, thermoplastics, composites orthe like. The carrier 18 may also be formed of woven or non-woven fabricmaterials, paper materials, impregnated fibers, fibrous materials or thelike. The carrier 18 preferably has a thickness between about 1 micronor less and 1 centimeter or greater, more preferably between about 10microns and 1 millimeter, still more preferably between about 50 micronsand about 200 microns.

One preferred material for the carrier is a polyester film that iscommercially available under the tradename MELINEX®, designation numberST505, from the DuPont Company. Another preferred material for thecarrier is a spunbound Olefin that is commercially available under thetradename TYVEK® also from the DuPont Company. Still another preferredmaterial for the carrier is a polyester film that is commerciallyavailable under the tradename CETUS®, designation number CP2101, fromthe Cetus Company. Yet another preferred material for the carrier is anylon polyester or polyether imide that is commercially available underthe tradename ULTEM®, designation number 1000 or otherwise, from theGeneral Electric Corporation.

Of course, other types of base substrate material are available for thecarrier such as ceramic, glass, polymeric material (e.g. plastic,elastomers, thermoplastic, thermoset, or the like), polyesters,polyethylene, Mylar, woven material (e.g. nylon or cloth), or otherwise.

Preferred carriers have advantageous properties such as strength,flexibility, rigidity, elasticity, dielectric properties, a combinationthereof or the like depending upon their application. Carriers may alsobe transparent, opaque, reflective or the like. Preferably, carriers aretemperature resistant (e.g. up to 80° C. or more). Furthermore, carriersmay exhibit relatively high acceptance to screen printing materials(e.g. polymers).

In preferred embodiments, particularly for seating applications, but forother applications as well, materials used for the carrier of thepresent invention exhibit an elongation at failure of as much or greaterthan 15%, more preferably greater that 35%, even more preferably greaterthan 50% and still more preferably greater than 70%. Also in preferredembodiments, the material used for the carrier of the present inventionexhibit a dielectric constant of up to or greater than 0.5, morepreferably greater than 1.0 and even more preferably greater than 2.0.

The first conductive medium 12 may be disposed upon the carrier 18 in avariety of configurations (e.g., in spaced parallel lines, zig-zags,serpentine, opposing interdigitated lines, etc.). Typically, the firstconductive medium 12 is divided into a first or negative section 70 anda second or positive section 72 that are spaced apart from each otherupon the carrier 18. Preferably, the negative section 70 does notdirectly electrically connect with the positive section 72. As usedherein the terms “positive” and “negative” are only used because one ofthe sections 70, 72 will be electrically connected to a positiveterminal of a power source while the other is electrically connected toa negative terminal as is further described below. It shall beunderstood that the sections 70, 72 may be interchanged or switched.Preferably, each of the sections 70, 72 respectively includes a baseportion 74, 76 and a plurality of extensions 80, 82 extending outwardlyfrom the base portions 74, 76. As shown, the plurality of extensions 80of one section 70 are spaced apart from the plurality of extensions 82of the other section 72. Moreover, the plurality of extensions 80 of thenegative section 70 are spaced apart from each other and the pluralityof extensions 82 of the positive section 72 are also spaced apart fromeach other.

In the particular embodiment illustrated, the base portion 74 of thenegative section 70 extends along substantially the entire firstlengthwise edge 32 of the carrier 18 while the base portion 76 of thepositive section 72 extends along substantially the entire secondlengthwise edge 34 of the carrier 34. As such both base portions 74, 76include the same indentations 38, 40, cavities 44, 46 and contours 48,50, 52 as the lengthwise edges 32, 34 of the carrier 18. The baseportions 74, 76 also include an opening 88 extending down the center ofthe base portions 74, 76 adjacent the indentations 38, 40, cavities 44,46 and contours 48, 50, 52.

The extensions 80, 82 are illustrated as elongated fingers that extendfrom one of the base portions 74, 76 toward the other of the baseportions 74, 76 without actually contacting the other of the baseportions 74, 76. As shown, particularly in FIG. 1, wherein only thefirst conductive medium 12 is disposed upon the carrier, the extensions80 of the negative section 70 are interdigitated or intermittent withrespect to the extensions 82 of the positive section 72 thereby forminggaps 90 between the extensions 80, 82.

The first conductive medium 12 may be formed of a variety of materialssuch as metals, conductive plastics, combinations thereof or the like.While it is contemplated that the first and second sections 70, 72 ofthe first conductive medium 12 may be formed of different materials, itis preferred that they be formed of one material. In a preferredembodiment, the first conductive medium 12 is formed of a polymericmaterial, which may be printed (e.g., screen printed) upon the carrier18.

As an exemplary embodiment, the material for the first conductive medium12 is a polymeric material such as a polymer thick film composition soldunder the tradename POLYMER SILVER CONDUCTOR 5025, commerciallyavailable from DuPont, 1007 Market Street, Wilmington, Del. 19898. Insuch an embodiment, the first conductive medium 12 is typically screenprinted upon the carrier 18 such that the medium 12 has a thickness ofabout 2 micrometers to about 4 millimeters, more preferably about 6micrometers to about 1 millimeter and even more preferably about 12 toabout 15 micrometers. Once printed, the conductive medium 12 istypically exposed to heat for curing. For example the carrier 18 andmedium 12 may be placed within a box oven and the medium 12 cured forabout 1 to about 10 minutes at a temperature between about 80° C. andabout 180° C., more preferably for about 3 to about 8 minutes at atemperature between about 100° C. and about 140° C., still morepreferably about 5 to about 6 minutes at a temperature of about 115° C.to about 125° C. As an alternative example, for a reel-to-reel screenprinter, the carrier 18 and medium 12 may be exposed to temperatures ofabout 100° C. to about 200° C. for about 20 seconds to about 3 minutes,more preferably temperatures of about 120° C. to about 160° for about 40seconds to about 2 minutes, still more preferably a temperature of about140° C. for about one minute for curing the medium 12.

While, one or more configurations for the base portions have beendiscussed, it is contemplated that the base portions of the presentinvention may be arranged in numerous alternative configurations aswell. As such, the base portions may be on opposite, adjacent or samesides of a carrier or may partially or completely overlapping having aninterposed insulating material. The shape of the base portions may begeometric or non-geometric. Similarly, the base portion may besymmetrical or asymmetrical in shape. Some possible base portion shapesinclude: shapes having one or more arcuate boarders (e.g. round,circular, elliptical, oval, helical, combinations thereof or the like),shapes having one or more linear boarders (e.g. rectangular, square,equilateral or the like). It is also contemplated that the base portionsmay include a variety of both arcuate and linear borders.

In other embodiments, one base portion may be partially or fullyenclosed within the other base portion. As an example, a first U-shapedbase portion could partially surround a second corresponding U-shapedbase portion with interdigitated or otherwise configured extensionsextending from the base portions. As another example, a first baseportion may be shaped in an enclosed configuration (e.g. as a circle,square, rectangle or the like) such that the second base (which may beof corresponding or non-corresponding shape) portion is substantiallyenclosed within the first base portion. In either example, the heatermay include extensions in any configuration described herein.

While only two base portions are shown, it is foreseeable thatadditional base portions may be used. Also, the number of electricallypositive base portions may or may not be equal to that of theelectrically negative base portions.

Accordingly, as with the base portions, the extensions can be arrangedin different patterns with respect to the base portions and each other.Some possible patterns include interdigitated serpentine, straight,curved, spiral, rectangular, zigzag, or otherwise. In the embodimentshown in FIG. 2, each first extension from the first base portion isseparated from the next closest first extension by no more than onesecond extension from the second base portions However, it iscontemplated that a first extension from the first base portion may beseparated from the next closest first extension by two or more secondextension from the second base portion. In such an embodiment, it ispreferably although not required that the second conductive mediuminterconnects only first extensions from the first base portion withsecond extensions from the second base portion.

Additionally, it is contemplated that two sections of the firstconductive medium may form an overlapping relationship in order tocreate a more desirable circuit for selective heat generation of theheater. For example, as illustrated in the embodiment shown in FIG. 9,though discussed in greater detail below, a first section of the firstconductive medium may be configured in an overlapping relationship witha second section. In such an instance, an insulating or nonconductingmaterial typically interposes the first and second sections, to preventcurrents from traveling directly from one section to another sectionwithout passing through the second conductive medium. Of course, directpassage of current between sections may be desirable in some instances(e.g. such that current only passes through a portion of the secondconductive medium). However, the first and second sections mayalternatively be interposed by the second conductive medium, orotherwise to provide a heating circuit. For example, a second conductivemedium may be sandwiched between a portion of the first and secondsection. As such, when a current travels from the first and secondsection, it is possible for the second conductive to generate heattherebetween.

This overlapping relationship of the different sections of the firstconductive medium provides the ability to form more intricate circuitdesigns. One advantage of having more intricate circuits is the abilityto generate multiple heat outputs from a single heating unit. Anotheradvantage is the ability to provide a heating unit having more then oneheating regions that are selectively activated.

In any of the possible base portion configurations, the width andthickness of the portion may be consistent throughout, variable, orprogressively narrowing or expanding. Likewise, the width and thicknessof an extension from the first or second base portions may beconsistent, variable, or progressively narrowing or expanding.Furthermore, the thickness, length and width of the first and secondextensions may vary throughout the heater. Moreover, the extensions maybe parallel, skew, nonparallel or the like relative to each other, thebase portions, the extensions from the other base portion or relative tothe second conductive medium.

As with the base portions, the extensions from either of the baseportions may overlap each other wherein nonconductive medium is placedbetween the overlapped regions.

The material of the base portion and the extensions may be the same ordifferent material depending on the application. Moreover, theextensions may be interconnected by the second conductive medium suchthat the base portions are connected.

Alternatively, it is contemplated that there are no extensions and thebase portions are in direct contact with a conductive medium. Examplesof this configuration includes the overlapping of the base portionshaving an interposed conductive medium. In another example, the baseportions may be configured adjacently, or otherwise, having a conductivematerial interposed. In the above examples, the application of more thantwo base portions may be desired.

Referring to FIGS. 2 and 3, the second conductive medium 14 may bedisposed upon the carrier 18 in a variety of configurations. The secondconductive medium 14 may be continuous, intermittent, planar, geometric,contoured, combinations thereof or the like. Preferably, the secondconductive medium 14 electrically connects the positive section 72 ofthe first conductive medium 12 with the negative section 70 of the firstconductive medium 12.

In the exemplary embodiment illustrated in FIG. 2, the second conductivemedium 14 includes a plurality of strips 94, which are shown as separatefrom each other, but which may be interconnected. Each of the strips 94is elongated and extends with and/or preferably parallel to theextensions 80, 82 of the first conductive medium 12 and each strip 94electrically connects an extension 80 of the negative section 70 with anextension 82 of the positive section 72. As shown, each of the strips 94overlaps and directly contacts one extension 80 of the negative section70 and one extension 82 of the positive section 72.

It is also for preferred, but not necessarily required, that each of theplurality of strips 94 have substantially the same size and shape andthat the strips 94 be substantially uniformly spaced apart from eachother. Moreover, it is preferable for the strips 94 to have uniformdensities compared to each other and throughout each strip 94. In thismanner, the heater 10 can typically produce a more uniform heatintensity along the length and/or width of the heater 10.

The second conductive medium 14 may be formed of a variety of materialsincluding metal, plastics or combinations thereof. Preferably, thematerial exhibits relatively high positive thermal coefficient (PTC) aswill be discussed further below. While it is contemplated that thestrips 94 may be formed of different materials, it is preferred thatthey be formed of one material. In a preferred embodiment, the secondconductive medium 14 is formed of a polymeric material, which may beprinted (e.g., screen printed) upon the carrier 18.

In an exemplary embodiment, the material for the second conductivemedium 14 may be a polymeric material such as a polymer thick filmcomposition sold under the tradename PTC CARBON RESISTOR 7282,commercially available from DuPont, 1007 Market Street, Wilmington, Del.19898. In such an embodiment, the second conductive medium 14 istypically screen printed upon the carrier 18 such that the medium 14 hasa thickness of about 1 micrometer to about 1 millimeter, more preferablyabout 3 micrometers to about 10 micrometers and even more preferablyabout 6 to about 8 micrometers. Alternate printing methods include silkscreen printing, ink jet printing or the like. Once printed, theconductive medium 14 is typically exposed to heat for curing. Forexample, the carrier 18 and medium 14 may be placed within a box ovenand cured for about 2 to about 30 minutes at a temperature between about90° C. and about 200° C., more preferably about 5 to about 15 minutes ata temperature of about 110° C. to about 150° C., still more preferablyabout 10 minutes at temperature of about 130° C. As another example, fora belt drier, the carrier and medium 14 may be exposed to temperaturesof about 110° C. to about 210° C. for about 1 minute to about 20minutes, more preferably temperatures of about 130° C. to about 170° forabout 2 minutes to about 10 minutes, still more preferably a temperatureof about 150° C. for about 3 to about 5 minutes.

Other conductive mediums used in the above printing methods includeaqueous polymers including conductive fillers (e.g. conductive metalpowder, metallic oxide, silver, copper or otherwise), resistive fillers(e.g. carbon or otherwise), films (e.g. polyurethane, UV curablePolymeric dielectric composition, thermosetting resins (e.g. epoxies,phenol resins, or the like), or otherwise), ethylene vinyl acetateco-polymer resin having black carbon or a combination thereof.Preferably, the ink is impermeable to light and may include one or moreof the following binders: resin-based acrylic ink, borosilicatelead-glass, thermosetting resins (e.g. epoxy, phenol, melamine resin),or conductive powder.

The second conductive medium may be applied in a variety of patternsalternative to that which is shown. In one embodiment, the conductivemedium may emulate (e.g. extend parallel) the pattern of the first andsecond base portion. Preferably, the conductive medium is at leastpartially interposed between the extensions of the first and second baseportions. When provided as strips or otherwise, the conductive materialmay be parallel, angled, skew, perpendicular, serpentine with respect tothe extensions of the base portions or the base portions themselves.Also the pattern of the second conductive medium may be comprised ofconcentric or non-concentric geometric configurations, e.g. circles,squares, oval, or otherwise. Furthermore, the second conductive mediummay be randomly or systematically place between extension of the baseportions, or between the base portions, and may comprise a plurality ofstrips having cut out portions. The strips of the conductive materialmay also be sectioned or broken into pieces.

While preferred material for the first and second conductive mediumshave been disclosed, it is contemplated that other materials may beemployed as layers or otherwise for providing part or all of the firstand second conductive mediums. Examples of these materials include: foiltape, transfer paper, strips sheets, sleeves, strands of electricallyconductive thread, wire, deposited metal, plated material, sewn materialor otherwise. Other materials include: metals (e.g. aluminum, chromium,nichrome, or otherwise), carbon, film, foam (either thermally or nonthermally conductive) (e.g. Comfortem® by foam international),electrically conductive woven fabric having a conductive coating such assilver, polymeric material (applied as a film or printed, discussed morebelow).

The heater 10 of the present invention also typically includes one ormore (e.g. a pair of) electrical connections 100, 102. Preferably, eachof the connections 100, 102 is respectively in electric communicationwith one of the base portions 74, 76 of the negative and positivesections 70, 72.

It shall be understood by those skilled in the art that a variety ofelectrical connections may be employed. In the particular embodiment ofFIG. 2, each of the electrical connections 100, 102 includes a wire 104(e.g., a coated copper conductive wire) having an end 106 that isattached (e.g. soldered) to a foil patch 108 (e.g., of electricallyconductive tape) and the patch 108 with the end 106 is attached (e.g.,adhered) to one of the base portions 74, 76. In an alternative exemplaryembodiment, and referring to FIG. 2A, an electrical connection 110 isemployed wherein a member 112 includes a rivet 114 connected to one ofthe base portions 74 and an eyelet 116 connected to a wire 120.

Advantageously, the heater of the present invention may be formed withonly one or two electrical connections for providing a current throughthe base portions, the extension, the second conductive medium (e.g. thestrips) or a combination thereof. Of course, additional connections maybe used if desired or needed. As an added value, the heater 10 can beformed with the entirety of the first and second conductors supported bythe single carrier 18 without requiring additional layers for supportingthe conductors. Of course, additional layers may be used if needed ordesired.

The electrical connections may be located on the same side of thecarrier. Alternatively, the electrical connections may be located onopposite or adjacent sides of the carrier. Also, the electricalconnections may be diagonally opposite each other on the carrier. Thus,the electrical connections may be situated such that the summation ofthe electrical paths between adjacent portions of the extension aresubstantially equivalent or substantially non equivalent.

The electrical connections may be integrated into a single unit, havingboth positive and negative leads, or may be separated into two or moreconnections. Furthermore, the electrical connections may be integratedinto a single extension or “tail”, or multiple “tails”, used toelectrically connect the heater to a power or energy source (e.g. abattery).

The heater of the present invention may be capable of operating at oneor multiple heat outputs. Various techniques may be used for producingmultiple heat outputs. For example, referring to FIGS. 8 and 9, two ormore circuits may be configured to operate at different output levelsand may be disposed or printed on one, two or more carriers.Alternatively, referring to any of the embodiments contained herein, twoor more sets of electrical connections could deliver different energylevels (e.g. voltages) to one, two or more circuits printed onto one,two or more carriers. Moreover, one, two or more electrical connectionsmay be configured for delivering different output levels for deliveringdifferent output levels to the above configured heaters.

The present invention may further comprise one or more control safetyfeatures including: thermostat, control module with Negative TemperatureCoefficient (NTC) resistor, Positive Temperature Coefficient fuse orsome other temperature sensing device. Also, a Constant TemperatureCoefficient (CTC) may be used for eliminating the effect of thetemperature of the heating element on the amount of heat generated bythe heating element. The above features can allow the system to shutdown upon sensing of excessive temperatures or a short in the system.

Also, the present invention may be configured with one or more switches(e.g. a latch switch or momentary switch), for applying a current to theheater of the present invention. For example, a control module may beused in conjunction with a momentary switch for turning the heatingdevice on and off. Alternatively, a switch (e.g. an on/off switch) maybe used to physically connect and/or disconnect a circuit that includesthe heater with an energy source. Other switches that may be usedincludes a voltage control potentiometer, multiple position switch forallowing choice of temperature settings (e.g. high-low-off), multi-poleswitch or otherwise.

The heater of the present invention is electrically connected to anenergy source to generate a current through the heater to produce heat.The energy source may provide an alternating current, a direct current,or a combination thereof. In an automotive application, preferably theheater is electrically connected to an automotive energy supply, (e.g.12 volt battery). Alternatively, or additionally, the heater may beconnected to the alternator, control module or other electricalcomponents in the vehicle.

In any of the discussed embodiments, including FIG. 3, an insulationlayer 130 may be laminated over the conductive mediums 12, 14 of theheater 10. The insulation layer 130 may be formed of fleece, gauze orthe like and may be fastened to the carrier 18 via adhesive orotherwise.

While FIG. 3 has been illustrated with an insulation layer 130, it iscontemplated that the heater 10 may advantageously be formed without anysuch additional insulation layer 130. Moreover, it is contemplated thatthe insulation layer 130 may be provided by the seat (e.g., as part of atrim layer) and that the insulation material may not be specificallyadhered or otherwise attached to the heater 10. The application of theinsulating material is numerous and at a minimum includes the methodsused below in applying the protective coating.

As another option, the first conductive medium 12, the second conductivemedium 14, or both may be fully or partially covered with a protectivecoating. In a preferred embodiment, the first and second conductivemediums 12, 14 are coated with a protective dielectric coating formed ofa polymeric dielectric composition. Preferably, the coating is curable(e.g., UV curable), solvent less or a combination thereof. The coatingmay be applied to the conductive mediums 12, 14 by several methods suchas printing, spraying, rolling, dabbing, brushing, pouring or the like,but is preferably screen printed upon the mediums 12, 14. The coatingmay be up to 5 millimeters thick or greater and is preferably betweenabout 10 microns and about 4 millimeters thick, more preferably betweenabout 100 microns and about 3 millimeters thick (e.g., between about 1to about 1.2 millimeters thick). In a preferred embodiment, theprotective layer has electrical, or thermal, insulating characteristics.

Materials available for both the insulating layer and protective layerinclude the same materials used for the carrier. Additional layers thatmay be used for the insulating and protective layers having di-electricproperties include: paper, film (e.g. polyurethane, UV curable polymericdielectric composition, thermosetting resins or otherwise), vinyl sheet,fleece, gauze, flexible sheets (e.g. elastomeric, polyesterterephthalate, polycarbonates, or otherwise), foam (e.g. thermallyconductive, non-thermally conductive, polyurethane, neoprene, orotherwise), glass or the like. However, a protective layer may beconductive in certain layered configurations.

In any of the embodiment of the present invention, it is contemplatedthat an adhesive is disposed on either side of the carrier or conductivemediums prior to the heater of the present invention being applied to aspecific article (e.g. a seat cover, mirror or otherwise). It is alsocontemplated that adhesives may be on both sides of the carrier toadhere to one or more additional components associated with the heatersuch as a protective layer or otherwise. Also, it is contemplated thatno adhesives are used in the present invention but instead staticelectricity or some other self attachment is used to mount or fix theheater to a specified region of the article.

Vehicle Seat and Mirror Applications

As previously discussed, the heater 10 of the present invention may beintegrated into various articles of manufacture. Referring specificallyto FIGS. 4 and 5, as an example, the heater 10 is shown integrated intoa seat 140 of a vehicle. The heater 10 of the present invention may belocated in various portions of an automotive vehicle seat such as asupport portion, a backrest portion, a shoulder support portion or aheadrest. The heater may be located between the trim of the seat and thefoam cushioning of the seat. The heater may also be integrated into thetrim of the seat, the foam cushioning of the seat or both.

Referring to FIG. 4, the seat 140 is illustrated with the heater 10 ofFIGS. 2 and 3 positioned in both a seat backrest component 142 and aseat support component 144. In the embodiment illustrated, eachcomponent 142, 144 of the seat 140 includes a trim layer 146 and a foamcushion 148 and each of the heaters 10 is positioned substantiallybetween the foam cushion 148 and trim layer 146. Preferably, each heater10 is fastened to the seat 140 (e.g., the trim layer 146, the cushion148 or both) for maintaining the heater 10 stationary relative to theseat 140. It is also contemplated that tape 150 (e.g., two-way tape), asshown in FIG. 3, or other fasteners or adhesives may be employed tofasten the heater 10 to the seat 140 and particularly the foam cushion148.

In a highly preferred embodiment shown in FIG. 5, a central portion 160of the heater 10 is tied down atop a foam cushion 162 of a seat with thecentral portion 160 extending at least partially into a cavity 164(e.g., a trench) of the cushion 162. As shown, tie strings 170 extendthrough the opening 58 over the top of the central portion 160 of theheater 10 to tie the heater 10 down. Advantageously, the contours 48,50, 52 of the carrier 18 and the first conductive medium 12 curve aboutfoam cushion 162 at the cavity 164 when the central portion 160 of theheater 10 is extended into the cushion 162 thereby relieving stress thatmight otherwise be placed upon the first conductive medium 12 andparticularly the base portions 74, 76 of the first conductive medium 12.Moreover, the opening 58 also serves to relieve stress as the centralportion 160 of the heater 10 is extended into the cushion. While thecontours 48, 50, 52 and opening 58 have been employed for relievingstress during application to a foam cushion 162, it should be understoodthat the contours 48, 50, 52 and opening 58 may also assist in relievingstress wherever the heater 10 curves about an object to which it isapplied.

In one alternate embodiment, the present invention is integrated with amirror assembly. In such an embodiment, the shape of the heater, carrieror both is likely to change to the corresponding shape of the mirrorassembly. An example of such an embodiment is shown in FIG. 6, whereinthe heater 10 is configured with a carrier 18, a first conductive medium12 and a second conductive medium 14.

The first conductive medium 12 is preferably configured with a firstbase portion 74 and a second base portion 76 having associated first andsecond oppositely charged electrical connectors 100, 102 respectively.Preferably, the shape of the first and second base portions 74, 76, thecarrier 18 or both conform to the shape of the mirror 12, backing orboth. Furthermore, it is contemplated that the first and second baseportions 74, 76 may have varying widths as they extend along the carrier14.

Extending from the first and second base portions 74, 76 are a pluralityof interdigitted first and second extensions 80, 82 having varyinglengths (e.g., becoming progressively larger or smaller) according tothe contours of the first and second base portions 74, 76 and thecontours of the mirror. Preferably the extensions 80, 82 are parallelwith respect to each other, however, other configurations arecontemplated as disclosed herein. Also, other patterns are contemplatedas disclosed herein.

Preferably, each of the sections 70, 72 respectively includes a baseportion 74, 76 and a plurality of extensions 80, 82 extending outwardlyfrom the base portions 74, 76. As shown, the plurality of extensions 80of one section 70 are spaced apart from the plurality of extensions 82of the other section 72. Moreover, the plurality of extensions 80 of thenegative section 70 are spaced apart from each other and the pluralityof extensions 82 of the positive section 72 are also spaced apart fromeach other.

Alternatively in another embodiment, referring to FIG. 7, the heater 10of the present invention may be applied to, or incorporated with, amirror assembly 180 (e.g. side mirror, rear view mirror, or the like).The mirror assembly 180 is typically configured with a mirror 182, amirror backing 184 and a housing 186, although each component is notnecessarily required. In the illustrated embodiment, the heater 10includes a carrier 18 that is attached to the mirror 182, the backing184 or both. Alternatively, however, it is contemplated that the mirror182 or backing 184 may be the carrier for the conductive mediums of theheater 10.

The carrier 18 may be applied to (e.g. attached to) the mirror 182, thebacking 184 or both using a variety of techniques. In one embodiment,the attachment of the heater 10 to the mirror 182 or backing 184 may beaccomplished with adhesives, fasteners, combinations thereof or thelike. Alternatively, the heater 10 may be attached without the use ofadhesives or fasteners. For example, the heater 10 may be staticallyadhered to the mirror 182 or backing 184. As another alternative, thecarrier 18 may be composed of a material having adhesive characteristicsfor adhering the heater 10 to the mirror assembly 180.

Alternatively or additionally, it is contemplated that the mirrorassembly may be configured for securing the heater 10 to itself. Forexample, the mirror 182, the backing 184 or both may include one or morerecesses for receiving and securing the heater 10 thereto. As anotherexample, the heater 10 may be sandwiched and secured between the mirror182 and the backing 184. Moreover, the mirror assembly 180 may beconfigured with integral fasteners (e.g. snap-fits) for securing theheater 10.

In addition to the first conductive medium 12 and the second conductivemedium 14, the electrical connectors 100, 102 may be directly attachedto the mirror 182, the backing 184 or both. Advantageously, any portionof the heater 10 not disposed or incorporated on a portion of the mirrorassembly 180, may be adhered or fastened to the mirror assembly 180using any of the techniques described herein. For example, the mirror182 or backing 184 may be coated with the second conductive medium 14while the first conductive 12 medium may be placed over the secondconductive 14 according to a different technique. Further, it iscontemplated that the mirror 182 contacts either the first conductivemedium, the second conductive medium or both. Optionally however, one ormore additional layers (e.g. insulating, protective, otherwise or acombination thereof) as described herein may be place over the firstconductive medium 12 as desired.

In operation, the heater 10 can operate to heat the mirror 182 insubstantially the same manner as the heater can be used to heat a seat.Advantageously, the heater can assist in removing water in the form ofcondensation, frost or otherwise from the mirror 182.

Operation

In operation, and referring to FIGS. 2 and 4 one electrical connection102 is connected to a positive terminal of an electrical power source(not shown) and the other connection 100 is connected to a negativeterminal of the electrical power source. In turn, when the power sourceprovides electrical energy to the heater 10, an electrical current flowsfrom one electrical connection 100 to the base portion 74 of thenegative section 70 of the first conductive medium 12. The electricitythen flows to the extensions 80 of the negative section 70 and throughthe strips 94 of the second conductive medium 14 to the extensions 82 ofthe positive section 72 of the first conductive medium 12. Thereafter,the electricity flows to and through the base portion 76 of the positivesection 72 of the first conductive medium 12 and out of the heater 10through the electrical connection 102. Due to the resistance of thesecond conductive medium 14, the strips 94 elevate in temperaturethereby heating the seat 10, and particularly the trim 146 of the seat140. Advantageously, the strips 94 of the second conductive medium 14exhibit positive thermal coefficient characterization such that thestrips 94 are self-limiting with regard to how warm they will become.More specifically, for a particular voltage applied to the secondconductive medium 14, the resistance of the second conductive medium 14will rise, which in turn, causes the current flowing through the secondconductive medium 14 to become lower until an equilibrium is attained.As will be recognized by the skilled artisan, various variables such asthe voltage applied to the heater, the composition of the secondconductive medium 14, the size and configuration of the secondconductive medium 14 and others may be varied such that the equilibriumfor the medium 14 is achieved at desired heat output. It is alsocontemplated that, after use, the resistance of the second conductivemedium may shift (e.g., upwardly shift) between about 15% and about 25%.If such is the case, it is typically desirable to design theconfiguration of the second conductive medium to account for the shiftwhile still producing the preferred heat output.

In preferred embodiments, the distance between the positive section ofthe first conductive medium and the negative section of the firstconductive medium (i.e., the distance that the second conductive mediumspans to interconnect the sections) may be set to assist in controllingthe temperature of the second conductive medium, the heater or bothduring operation. In the preferred illustrated embodiment, theextensions 82 of the positive section 72 are typically separated fromthe extensions 80 of the negative section 70 by a distance of about 0.5millimeter to about 1 centimeter, more preferably about 1.5 millimetersto about 5 millimeters, still more preferably about 3 millimeters. Alsoin the preferred embodiment, the second conductive medium 14, the heater10 or both reach a temperature between about 0.0° C. and about 100° C.,more preferably between about 25° C. and about 80° C., still morepreferably between about 50° C. and about 70° C.

In addition to the previous embodiments, it is also contemplated withinthe scope of the present invention that the heater can include a firstconductive medium having at least three sections, which are interposedby a second conductive medium. In such an embodiment all three sectionsof the first conductive medium can be electrically connected through thesecond conductive medium thereby providing the ability to form multipleheating circuits. For example, one or more circuits may be createdbetween a first and second section, the first and third sections, thesecond and third section or between all three sections. Also, with theuse of a first conductive medium having at least three sections,numerous circuits may be selectively generated between any two sectionshaving an interposed second conductive medium. As such, preferredheating regions may be generated.

In this alternate configuration, one section of the first conductivemedium is connected to a first or positive terminal and another sectionis connected to a second or negative terminal of a power supply forforming a first heating circuit. By connecting yet another section ofthe first conductive medium to the positive or negative terminal of apower supply, a second heating circuit may be generated between thissection and any other section (e.g., the aforementioned sections oradditional sections) connected to an oppositely charged terminal.

Advantageously, a switching device, as disclosed herein, may be used forselectively and electrically connecting the sections of the firstconductive medium to the positive or negative terminal of a powersupply. Moreover, it should be understood that the materials discussedfor the carrier, the first and second conductive mediums may also beappropriately employed in the following embodiments and may be appliedas previously discussed. It is also contemplated that the followingembodiments may include an insulation layer that may be formed of thesame materials and applied to the carrier, the conductive medium or acombination thereof as described in the previous embodiments.

Accordingly, as shown in FIGS. 8 and 9, (FIG. 9 reference numbers inbrackets) there are illustrated two examples of an exemplary heater 190(290) that is configured with a first conductive medium 192 (292) havingat least three sections applied to a carrier 194 (294). The at leastthree sections include a first section 202 (302), a second section 204(304) and a third section 206 (306). Preferably, the first, second andthird sections 202, 204 and 206 (302, 304 and 306) are each respectivelyconfigured with a base portions 208, 210 and 212 (308, 310 and 312) anda plurality of extensions 214, 216 and 218 (314, 316 and 318)respectively extending from the base portion 208, 210 and 212 (308, 310and 312). As with the other embodiments contained herein, it iscontemplated that each of the first, second and third sections 202, 204and 206 (302, 304 and 306) are further configured with electricalconnections 220 (330) adapted for connecting the at least three sectionsto a power source. Advantageously, a control device (e.g., a switchingdevice or other device) is used for selectively connecting the at leastthree sections to a positive or negative terminal of a power supply.

Generally it is contemplated that sections of the first conductivemedium 192 (292) may be connected through the second conductive medium226 (326). For example, it is contemplated that any extension, baseportion, or other part of a section may be connected to any otherextension, base portion or other part of a section through anapplication of the second conductive medium 226 (326) over a portion orall of the carrier 194 (294). In this exemplary embodiment, the firstconductive medium 192 (292) is applied to the carrier 194 (294) and isoptionally partially or fully covered by a second conductive medium 226(326). As such, a completed circuit may be achieved by electricallyconnecting i) the power supply, ii) any section of a first conductivemedium, iii) the second conductive medium, and iv) any other section ofa first conductive medium, wherein each completed circuit may heatdifferent portions of the heater and/or change its heat output.Advantageously, a switching device may be utilized to selectively directcurrent through the first and second conductive medium.

A user can energize any two sections of the at least three sections toheat a region of the second conductive medium located between the twosections. Likewise, a user can energize more than two sections, of theat least three sections to heat additional regions of the secondconductive medium to increase the overall heat output of the heater 190(290).

Referring to FIG. 8 in more detail, a portion of the heater 190 isconfigured with a first conductive medium 192 applied to a carrier 194.The first conductive medium 192 is configured with at least threesections, namely the first, second and third sections 202, 204 and 206.

The first section 202 is preferably centrally located with respect tothe width of the carrier 194 and comprises a base portion 208 thatextends along the length of the carrier 194. Extending transverse to thelength of the carrier 194 is a plurality of spaced apart extensions 214,which are preferably skew (e.g. substantially perpendicular) to thefirst base portion 208. Advantageously, the extensions may extend outfrom one or both sides of the first base portion 208 and optionally,extensions extending from one side may be aligned or staggered relativeto extensions extending from the opposite side. Though not shown, thefirst section 202 is connected to a switching device, which selectivelyconnects the first section 202 to either a negative or positive terminalof a power supply.

The second section 204 comprises two base portions 210 which extendalong the length of the carrier 194 and preferably coextensive (e.g.,substantially parallel) with the first base portion 208. As with thefirst base portion 208, the second base portions 210 are configured witha plurality of spaced apart second extensions 216 that extendtransversely relative to the length of the carrier 194 and arepreferably skew (e.g., substantially perpendicular) to the second baseportions 210. As with the first extensions 214, the second extensions216 extend from both sides of the second base portions 210. However, incontrast to the first extensions 214, the second extension 216 areextending from one side of the base portions 210 the are shown asstaggered with respect to extensions 216 extending from the other sideof the base portions 210 but may alternatively be in an alignedconfiguration.

Advantageously, the spaced apart second extensions 216 interpose thefirst extensions 214 and are in an interdigitated configuration. Thefirst and second extension are spaced apart from each other andinterposed by strips of second conductive medium 226, or otherwise,which preferably overlaps at least a portion of the first and secondextensions 214, 216. In the embodiment shown, the second conductivemedium 226 that is located between the first and second extensions 214,216 forms a first heat region 228. Both of the second base portions 210are connected to a switching device, which can selectively connect thesecond section 204 to the terminal, opposite in charge, to the firstsection 202.

The third section 206 comprises a single third base portion 212 whichextends about the periphery of at least a portion of the carrier 194 andmore preferably about the majority of the periphery. However, it shouldbe appreciated that it is not necessary for the third base portion toextend about the majority of the periphery as the third base portion 212may be segmented into two or more third base portions 212. As with thefirst and second base portions 206, 208, the third base portion 212 isconfigured with a plurality of spaced apart third extensions 218 thatextend transversely relative to the length of the carrier 194 andpreferably extend skew (e.g. substantially perpendicular) to the thirdbase portion 212. In this exemplary embodiment, the third extensions 218extend from one side of the third base portions. In this configuration,the extensions of the third section extend inward toward the second baseportions so as to become interposed and interdigitated with secondextensions 216 that extend toward the third base portion.

The second and third extensions 216, 218 are spaced apart from eachother and interposed by strips of second conductive medium 226, orotherwise, which preferably overlaps at least a portion of the secondand third extensions 216, 218. The second conductive medium 226 locatedbetween the second and third extensions 216, 218 form a second heatingregion 230. The third base portion 212 is connected to a switchingdevice, which selectively connects the third section 206 to theterminal, opposite in charge, to either the first section 202 or thesecond section 204. Preferably the third base portion 212 is selectivelyconnected to the terminal which is opposite in charge to the secondsection 204.

Referring to FIG. 9 in more detail, a portion of a heater 290 isconfigured with a first conductive medium 292 applied to a carrier 294.As with the exemplary embodiment illustrated in FIG. 8, the firstconductive medium 292 is configured with at least three sections, namelythe first, second and third sections 302, 304 and 306. However, in thisconfiguration at least one overlapping relationship exits between the atleast three sections.

The first section 302 is preferably centrally located with respect tothe second and third section 304, 306 and comprises a base portion 308that extends along the length of the carrier 294. Extending transverserelative to the length of the carrier 294 is a plurality of spaced apartextensions 314 (though only one is shown), which are preferably skew(e.g., perpendicular) to the first base portion 308. The extensions 314are shown as extending from one side of the first base portion 308, butmay extend out from one or both sides of the first base portion 308.Preferably, The first section 302 is connected to a switching devicethrough an electrical connection 320, which selectively connects thefirst section 302 to either a negative or positive terminal of a powersupply.

The second section 304 comprises a second base portion 310 extendingalong the lengthwise edge of the carrier 294. The second base portion310 is shown as being substantially coextensive with (e.g., parallel to)and adjacent the first base portion 308, although not necessarilyrequired. The second section 302 is typically connected to a switchingdevice through an electrical connection 322, which selectively connectsthe second section 302 to the negative or positive terminal of the powersource. Preferably, the second section 302 is selectively connected to aterminal different than the first section 302 (e.g., the first sectionis selectively connected to a positive terminal when the second sectionis connected to a negative terminal and vice versa). As with the firstbase portion 308, the second base portions 310 is configured with aplurality of spaced apart second extensions 316 that extend transverserelative to the length of the carrier 294 and the extensions 316 arepreferably skew (e.g., substantially perpendicular) to the second baseportion 310. Due to the centrally located configuration of the firstsection 302 (e.g., between the second and third sections), the secondextensions 316 are shown in an overlapping relationship with the firstbase portion 308.

In one configuration, the first base portion 308 and the secondextensions 316 may be directly in contact with each other. However, in apreferred arrangement, the first base portion 308 and the secondextensions 316 are spaced apart by a spacer 332. One example of a spacer332 comprises a substantially electrically non-conductive orelectrically insulating material located between the first base portion308 and the second extensions 316. Though non-conductive materialsavailable for such an application are numerous, a few examples mayinclude glass, plastic, rubber, elastomeric or polymeric materials orotherwise and may be applied using any technique contained herein orotherwise. It is also contemplated that the material describedpreviously for the insulative layer may also be employed.

In another example, the spacer 332 may comprise a layer of secondconductive medium 326. In such a configuration, the spacer may generateheat with the application of a current traveling through the spacer(e.g., second conductive medium 326) from the first base portion 308 tothe second extensions 316 or vise versa.

Advantageously, the spaced apart second extensions 316 interpose thefirst extensions 314 and are in an interdigitated configuration. Thefirst and second extension are spaced apart from each other andinterposed by strips of second conductive medium 326, or otherwise,which preferably overlaps at least a portion of the first and secondextensions 314, 316. The second conductive medium 326 located betweenthe first and second extensions 314, 316 form a first heat region 328.Both of the second base portions 310 are connected to a switchingdevice, which selectively connects the second section 304 to theterminal, which is opposite in charge to the first section 302.

The third section 306 comprises a base portion 312 extending along alengthwise edge, opposite to the second base portion 310, of the carrier294 and is coextensive with (e.g., parallel to) the first base portion308. Preferably, The third section 304 is connected to a switchingdevice through an electrical connection 324, which selectively connectsthe third section 304 to either the negative or positive terminal of apower supply. Preferably, the third section 306 is connected to anoppositely charged terminal than that of the second section 304,although not required.

As with the first and second base portion 306, 308, the third baseportion 312 is configured with a plurality of spaced apart secondextensions 318 that extend transverse relative to length to the carrier294 and preferably extend skew (e.g. perpendicular) to the third baseportion 312. In the configuration depicted, the extensions extendtowards the first and second base portions 308, 310 and are interposedby the first and second extensions 314, 316.

Advantageously, the spaced apart third extensions 318 interpose thefirst and second extensions 314, 316 and are in an interdigitatedconfiguration. The second and third extensions 316, 318 are spaced apartfrom each other and interposed by strips of a second conductive medium326, which preferably overlaps at least a portion of the second andthird extensions 316, 318. The second conductive medium 326 locatedbetween the second and third extensions 316, 318 form a second heatregion 330. The third base portion 312 is connected to a switchingdevice, which selectively connects the third section 306 to theterminal, opposite in charge, to either the first section 302 or thesecond section 304. However, preferably the third base portion 312 isselectively connected to the terminal which is opposite in charge to thesecond section 304, although not required.

It should be appreciated that the patterns shown in FIGS. 8 and 9 mayrepeat throughout a portion of the carrier or the entire carrier. Itshould also be appreciated that the exemplary embodiment shown in FIGS.8 and 9 may be configured with any of the advantages as disclosedherein. For example, any of the materials, patterns, methods, additionalfeatures or otherwise, as previously discussed in other embodiment orotherwise contained herein, may be included with the exemplaryembodiments contained in FIGS. 8 and 9. Likewise, any of the featuresdisclosed in FIGS. 8 and 9 may be wholly, or in part, included with anyother embodiment or example contained herein to form the presentinvention.

Operation of the Heaters of FIGS. 8 and 9

Turning to a discussion of operation, referring to exemplary embodimentshown in FIG. 8, the heater 190 is illustrated having circuitryconfigured to enable the selection of one or more regions to be heated,to control the amount of heat output from the heater 190, or acombination thereof. As previously discussed, the heater 190 isconfigured with a first conductive medium 192 having at least threesections 202, 204 and 206, which are interposed by a second conductivemedium 226 and selectively connected to a positive or negative terminalof a power supply. As such, any two sections of the first conductivemedium 192 that are connected to oppositely charged terminals of a powersupply form a circuit and thereby generates heat in the region locatedtherebetween.

In a first mode of operation, a switching device (not shown)electrically connects the first section 202 of the first conductivemedium 192 to a positive or negative terminal of a power source andconnects the second section 204 to the other terminal. The connectioncreates a circuit for flowing electric current between the first andsecond sections 202, 204 through the second conductive medium 226. Asdiscussed earlier, the application of a current through the secondconductive medium 226 results in the generation of heat in the secondconductive medium 226 located between the first and second sections 202,204 thereby creating the first heated region 228. Also as discussedearlier, the amount of heat output is typically dependent upon thecircuit's configuration such as dimensions (e.g. width, thickness or thelike) of the conductive materials, properties (e.g., conductivity, PTCcharacteristics or the like) of the second conductive medium, currentbeing applied to the second conductive medium or otherwise.

In the particular embodiment illustrated, the first heated region 228,is generally defined by the second conductive medium located between thefirst and second extensions 214, 216. As such, the first heated regionmay be considered, in the first mode of the exemplary embodiment of FIG.8, as the area located between the upper most first extension 214 andthe lower most second extension 216. However, it should be appreciatedthat the definition of the heated region is dependent on the flow ofcurrent through the second conductive medium 226. As such, alternateapplications of second conductive medium, or the change in the directionor amount of current or otherwise, may change the location or size ofthe first heat region 228. For example, with the first extensions 214extending from both sides of the first base portion 208, withinterposing second extension 216, the first heated region 228 maycomprise the second conductive medium 226 interposed between the firstand second extensions 214, 216 on either side of the first base portion208 or both sides. Alternatively, the first heated region 228 may bedivided into two separate heat regions as so desired. As such, in thisexample, it is contemplated that one or both of the second base portions210 are electrically connected to an opposite terminal of a power supplyto that of the first base portion 208.

In a second mode of operation, the switching device selectively connectsthe first section 202 of the first conductive medium 192 to the positiveor negative terminal of a power source and the third section 206 to theother terminal. This connection creates a circuit between the first andthe third sections 202, 206 through the second conductive medium 226thereby resulting in the heating of the second conductive medium 226located there between. As such, a second heated region 234 is generatedin this mode of operation.

In a more descriptive discussion of the second mode, as electric currentleaves the first extensions 214, it travels through the secondconductive medium 226, through the non-connected second section 204and/or extensions thereof, through the second conductive medium 226again, and into the third extension 218. Of course, alternate currentpaths are also contemplated within the scope of the present invention.For example, the second conductive medium 226 may electrically bridgethe second section (e.g., through use of insulation materials). In suchan embodiment, the area between the first and third extensions 214, 218could generally defines the second heat region 234. Also, as in thefirst mode of operation, with the first extensions 214 extending fromboth sides of the first base portion 208, with adjacently located thirdextensions 218, the second heated region 234 may comprise the secondconductive medium 226 interposed between the first and third extensions214, 218 on either side of the first base portion 208 or both sides.Alternatively, second heated region 234 may be divided into two separateheat regions as so desired. As such it is contemplated that one or bothof the third base portions 212 are selectively and electricallyconnected to an opposite terminal of a power supply to that of the firstbase portion 208.

In this second mode of operation, it is foreseeable that not only doesthe heat region change in location and size, but also the amount of heatbeing generated may vary due to the difference in area or amount ofsecond conductive medium 226 subject to the applied current.

In a third mode of operation, the switching device selectively connectsthe second section 204 to the positive or negative terminal of a powersource and the third section 206 to the other terminal. This creates acircuit between the second and third extensions 216, 218 through thesecond conductive medium 226 thereby resulting in the heating of thesecond conductive medium located there between. As such, the thirdheated region 230 is generated.

Similar to that of the first heat region 228, the second heated regionis generally defined by the second conductive medium located between thesecond and third extensions 216, 218 and may include any extensionlocated there between. As such, the heated region may be considered, inthe third mode, as the area located between the upper most secondextensions 216 and the lower most third extensions 218. However, aspreviously discussed, it should be appreciated that the definition ofthe heated region is dependent upon the flow of current through thesecond conductive medium 226. Again, similar to that of the first modeof operation, with the second extensions 216 extending from both of thesecond base portion 210, with interposed third extensions 218, the thirdheated region 230 may comprise the second conductive medium 226interposed between the second and third extensions 214, 218 adjacent toeither of the second base portion 210 or both base portions 210.Alternatively, second heated region 234 may be divided into two separateheat regions as so desired. As such it is contemplated that one or bothof the second or third base portions 210, 212 are selectively andelectrically connected to an opposite terminal of a power supply to thatof the other second or third base portions 210, 212.

In the third mode of operation, the heat output will likely be similarto or the same as with the heat output of the first mode due to thesimilarity in spatial relationship and the amount of second conductivemedium 226 located between the extensions 216, 218. However, differentlyconfigured sections and/or materials could produce variable differentheat outputs.

In a fourth mode of operation, the switching device selectively connectsthe first and third sections 202 and 206 to the positive or negativeterminal of a power source and the second section 204 to the otherterminal. This creates a circuit between first and second extension 214,216 and the second and third extensions 216, 218 through the secondconductive medium 226. This mode of operation is substantially the sameor similar to the simultaneous operation of first and third mode becausethe first and second heat regions 228, 230 are being heated at leastpartially at the same time. As such, the heat output, in the fourthmode, may be the sum of the output found in the first and third mode ofoperation (e.g., approximately double the heat output). Of course, suchsummation of heat outputs assumes the same levels of current crossingthe second conductive medium 226 as in the first and third mode ofoperation. It is also contemplated that various voltage levels may beapplied to offer different heat output levels.

With the selective application of the four modes of operation, asdescribed above, it is possible to have at numerous heat output levels.For example, a lowest heat output level may comprise the second heatregion 234 on one side of the first base portion 208 due to the reducedamount of second conductive medium 226 being subjected to an electricalcurrent as compared to other heat regions (e.g., 228, 230). A higherheat output level may comprise the second heat regions 234 located onboth sides of the first base portion 208. Yet a still higher heat outputlevel may comprise the first heat region 228 or third heat region 230 asdescribed above, or combinations thereof. It should be apparent thenumerous heat output levels may be created with the three heat regions.It should also be apparent that this is but one circuit configuration ofthe present invention and with the addition of other configurationscomes the ability to create yet more circuits and heat output levels.

Now referring to the exemplary embodiment shown in FIG. 9, the heater190 again is illustrated having circuitry configured to enable theselection of one or more regions to be heated, the one or more amountsof heat output from the heater 190, or a combination thereof. Aspreviously discussed, the heater 190 is configured with a firstconductive medium 192 having at least three sections 202, 204 and 206,which are interposed by a second conductive medium 226 and selectivelyconnected to a positive or negative terminal of a power supply. As such,any two sections of the first conductive medium 194 that are connectedto oppositely charged terminals of a power supply can form a circuit andthereby generate heat in the region located there between.

As discussed, the heater 290 of FIG. 9 includes an overlappingrelationship between its sections and the overlapping portions mayinclude a spacer 332 located therebetween for preventing a current fromshorting or traveling to an undesired location or otherwise. Though, attimes, it may be desirous to electrically connect the overlappingportions of the first and second sections 302, 304 or alternatively,interpose a second conductive medium 326 there between for thegeneration of yet another heating region.

Typically, the spacer 332 comprises a substantially non-conductivematerial so that opposite currents can travel through the overlappingportions of first and second sections 302, 304 without causing a shortor otherwise interfering with current flow.

In a first mode of operation, a switching device (not shown)electrically connects the first section 302 of the first conductivemedium 292 to a positive or negative terminal of a power source andconnects the second section 304 to the other terminal. The connectioncreates a circuit between the first and second extensions 302, 304through the second conductive medium 326 and generates the first heatregion 328. The first heated region is generally defined by the secondconductive medium 326 located between the first and second extensions314, 316, but may be otherwise defined.

In a second mode, the switching device selectively connects the firstsection 302 to the positive or negative terminal of a power source andthe third section 306 to the other terminal. This connection results inthe heating of the second conductive medium 326 located between thefirst and second extensions 314, 316 and the second and third extensions316 and 318. Therefore, in this configuration, the heated regions 328and 330 will produce heat as the current will travel from the firstextensions 314 through the second conductive medium 326, through thenon-connected second extensions 316, through the second conductivemedium 326 again, and into the third extension 318.

Assuming continuity in the illustrated pattern of the heater, this modeof operation can result in heating all strips of conductive material.However, with different extension arrangements or discontinuities in theapplication of the second conductive medium 326, the heating of theentire carrier 294 may be less than complete.

In a third mode, the switching device selectively connects the secondsection 304 to the positive or negative terminal of a power source andthe third section 306 to the other terminal. This connection results inthe heating of the second conductive medium 326 located between thesecond and third sections 304, 306 thereby generating heated region 330.Assuming size and spatial similarities between the second and thirdextension, as compared to the first and second extension, the amount ofheat generated in this mode can be similar to that of the first mode. Ofcourse, changes in size and spatial relationship can provide differentheat outputs.

In a fourth mode, the switching device selectively connects the firstand third sections 302 and 306 to the positive or negative terminal of apower source and the second section 304 to the other terminal. Thisconfiguration results in the second conductive medium 326 locatedbetween the first and second extension 314, 316 and the second and thirdextension 316, 318 being heated, e.g. the first and second heat regions328, 330.

The amount of heat generated in this fourth mode may or may not besimilar to that of the second mode due to the amount of secondconductive medium 326 being subjected to a current, the distance betweenthe extensions, or otherwise or combinations thereof. However, incontrast to the second operation mode, it is contemplated that theamount of current traveling through the circuit may increase due to theadditional extension (e.g. second extension 314) applying a current. Assuch, the amount of heat output may increase or the elapsed timerequired to heat the heater may decrease or both.

It should be appreciated that circuitry illustrated in both FIG. 8 andFIG. 9 may comprise all or a portion of a given heating circuit.Likewise the circuits may be combined with each other or any othercircuits to form the heater of the present invention.

Also, while the second conductive medium is illustrated between all ofthe extension, it should be appreciated that the second conductivemedium may be selectively applied between the extensions therebychanging the flow of current through the sections of the heater, thesecond conductive medium or both.

Although the heaters illustrated include two or three sections, it iscontemplated that the heaters may be configured with more than three orless than two sections, which can be selectively connected to a powersupply.

Furthermore, it is contemplated that the current applied to any of thecircuits contained herein may be controllably varied to achieve adesired heat output. For example, a control unit may be utilized toapply a first voltage to the heater in a first mode and apply a secondvoltage in a second mode, which may be higher or lower than the firstvoltage. As such, the application of power to the circuit may vary,which may further vary the heat output of the heater.

In these later embodiments, as exemplified through FIGS. 8 and 9, it iscontemplated that any of the additional features that may be used withthe heater of the present invention, as discussed with other embodimentcontained herein or otherwise, may also be used in these laterembodiments. As an example, additional layers may be used, which mayinclude insulating, adhesive or protective layers. Likewise, these laterembodiments may be used in any of the application as contained herein(e.g., seats, mirrors, steering wheels or otherwise).

Unless stated otherwise, dimensions and geometries of the variousstructures depicted herein are not intended to be restrictive of theinvention, and other dimensions or geometries are possible. Pluralstructural components can be provided by a single integrated structure.Alternatively, a single integrated structure might be divided intoseparate plural components. In addition, while a feature of the presentinvention may have been described in the context of only one of theillustrated embodiments, such feature may be combined with one or moreother features of other embodiments, for any given application. It willalso be appreciated from the above that the fabrication of the uniquestructures herein and the operation thereof also constitute methods inaccordance with the present invention.

The preferred embodiment of the present invention has been disclosed. Aperson of ordinary skill in the art would realize however, that certainmodifications would come within the teachings of this invention.Therefore, the following claims should be studied to determine the truescope and content of the invention.

1. A heated seat comprising: a seat with a cavity; a heater overlayingthe seat, the heater including; i) a polymeric film flexible carrierthat includes a cutout on a first lengthwise edge and a secondlengthwise edge that are aligned so that the carrier has a narrowerwidth, and the narrower width is inserted into the cavity of the seat;ii) a base portion; iii) a first conductive medium screen printed uponthe carrier wherein the first conductive medium includes: 1) a negativesection having a plurality of first extensions; and 2) a positivesection having a plurality of second extensions; and iv) a second screenprinted conductive medium that includes a plurality of strips, each ofthe strips in overlapping relation with one of the plurality of firstextensions and one of the plurality of second extensions, the pluralityof strips also extending substantially parallel to the first and secondextensions
 2. The heated seat as in claim 1, wherein the firstconductive medium cooperatively defines the cutout, which bends about acontour of the seat.
 3. The heated seat as in claim 2, wherein thecarrier of the heater has an hour-glass shape.
 4. The heated seat as inclaim 3, wherein the carrier of the heater has a centralizedthrough-hole opening defined adjacent the cutout.
 5. (canceled)
 6. Theheated seat as in claim 4, wherein the only electrical connections ofthe heater are a first electrical connection and a second electricalconnection.
 7. The heated seat as in claim 1, wherein the plurality ofstrips are substantially uniformly spaced apart from each other.
 8. Theheated seat as in claim 1, wherein each strip of the plurality of stripshas substantially the same shape.
 9. The heated seat as in claim 1,wherein each strip has a substantially continuous density throughout.10. The heated seat as in claim 1, wherein the carrier is formed of amaterial having a dielectric constant greater than
 1. 11. The heatedseat as in claim 1 wherein the carrier is formed of a material having anelongation at failure greater than 15%.
 12. The heated seat as in claim1 wherein the carrier is formed of a material having an elongation atfailure greater than 50%. 13-44. (canceled)